Light-radiation congruence with gantry angle using the electronic portal imaging device
Keywords:
Quality assurance, x-ray/Light field congruence, electronic portal imaging device, EPIDAbstract
In the present work, a template and an own software are presented in order to perform the light-radiation congruence test in linear accelerators (LINAC) in a fast and precise way, using the electronic portal imaging device (EPID). The validation of the set template-software is carried out by means of comparison with radiographic film, an external software and displacing the collimation system. Subsequently, a study of the influence of the gantry rotation on the coincidence test in three LINACs is carried out. For the assessment of the coincidence with the gantry angle, in addition to the traditional parameters, a new parameter is proposed that evaluates the coincidence of the light and radiated areas. The variation of the coincidence with the gantry angle obtained for the three employed LINACs is not significant. The results of the study allow us to conclude that a single series of measurements (for 0º, 90º and 270º gantry) is enough to perform an evaluation of the congruence with an uncertainty of less than 1 mm. In other words, the developed set allows an evaluation of the test for several gantry angles with an assumable uncertainty.
References
Pinza Molina C, Lliso Valverde F. Control de Calidad En Aceleradores de Electrones Para Uso Médico. Madrid: SEFM; 2009.
Klein EE, Hanley J, Bayouth J, et al. Task Group 142 report: Quality assurance of medical accelerators. Med Phys 2009;36(9):4197-212. https://doi.org/10.1118/1.3190392
Meijer G, van Kleffens H, Mijnheer B. Quality Control of Medical Linear Accelerators: NCS; 1996.
W.P.M. Mayles RL. Physics Aspects of Quality Control in Radiotherapy. York: IPEM; 1999. https://doi.org/10.1088/0031-9155/45/3/501
Swiss Society of Radiobiology and Medical Physics. Quality Control of Medical Electron Accelerators. Swiss Society of Radiobiology and Medical Physics; 2014.
Ho A, Thomadsen B, Paliwal B. On visual interpretation of light localization/radiation field coincidence films. Med Phys 1995;22(2):237-8. https://doi.org/10.1118/1.597601
Polak W, O’Doherty J, Jones M, et al. Automated x-ray / light field congruence using the LINAC EPID panel. Med Phys 2013;031718(3):031718. https://doi.org/10.1118/1.4793263
Dunscombe P, Humphreys S, Leszczynski K. A test tool for the visual verification of light and radiation fields using film or an electronic portal imaging device. Med Phys 1999;26(2):239-43. https://doi.org/10.1118/1.598522
Prisciandaro JI, Herman MG, Kruse JJ. Utilizing an electronic portal imaging device to monitor light and radiation field congruence. J Appl Clin Med Phys 2003;4(4):315-20. https://doi.org/10.1120/1.1621374
Klein EE, Hanley J, Bayouth J, et al. Task group 142 report: Quality assurance of medical accelerators. Med Phys 2009;36(9):4197-212. https://doi.org/10.1118/1.3190392
Downloads
Published
Issue
Section
How to Cite
